Big Monopoles, BPA and Autism-DNA Link
Oct 8 at 4:04pm by Aileen
NASA/JPL-Caltech/Kreck
News this week from the rarified realm of science research is both interesting and far-reaching. And no, by far-reaching I’m not talking about discovery that the planet Saturn has a huge, invisible ring nobody noticed before.
In the field of physics, some may have heard of Paul Dirac’s postulated magnetic monopoles – the quantum of the magnetic force, with a single pole instead of two. Dirac postulated that these must exist, and led to his famous ‘strings’ (which eventually led to some current GUT models). But nobody has ever actually ‘seen’ a monopole, so it’s been an open question of whether such beasties exist. Now, an NIST research team believe they’ve found the next best thing, monopoles the size of molecules!
They of course aren’t real monopoles, but apparently behave the same predicted way. Thus these synthetic compounds could allow scientists to do further research in the lab rather than just on paper napkins. They will be testing monopole predictions with these spin ice molecules, such as whether the postulated particles obey Coulomb’s Law. Stay tuned, this could get fascinating quickly!
Next up is a study about the ubiquitous BPA body burdens 93% of us carry around these days. BPA is a common chemical found in some plastics and epoxy resins. A paper published in Environmental Health Perspectives this week from researchers at Simon Fraser University, UNC-CH and Cincinnati Children’s Hospital linked prenatal BPA exposure to unusually aggressive, hyperactive behavior in 2-year old girls.
Neurodevelopmental disorders – ADD, ADHD, the Autism spectrum, etc. – have been most prevalent in young boys, who represent some 80% of the diagnoses. Further research on this environmental contaminant should be watched, as if the connection is solid, we can expect more and more young girls to suffer the same sorts of problems. BPA has also been linked to fertility problems, growth retardation and learning disorders as well as permanent changes to DNA in mice.
Speaking of Autism’s spectrum of neurodevelopmental disorders, researchers from MIT and the Center for Human Genetic Research at Massachusetts General Hospital have discovered that a single letter change in DNA may be indicative of Autism. This is known as a Single Nucleotide Polymorphism [SNP], and researchers tied it to chromosomes 5, 6, 20. The gene on chromosome 5 is associated with neuron development and autistic children showed lower expression.
This is just one piece of what researchers expect is a highly complex genetic puzzle, but it might lead to tests that can identify those at risk of producing autistic children, and identifying it in children very early. It also could help lead to specific treatments in the future. Progress is being made at last in dealing with this spectrum as a real medical condition and not just an indicator of lousy parenting skills. Which has been one of the most hurtful urban myths ever propagated by people who had no idea what they were talking about. That some of them were psychologists and physicians is sad, so we can all be thankful that some real answers are coming in.
Popularity: 43% [?]
Great Green Gobs of Greasy, Glowing… Marmosets?
May 29 at 5:05pm by Aileen
Green Glowing Monkey Paws
Well, I’ve got to admit this much-touted development in the world of medical research took me somewhat by surprise. Mostly because it caused me to stop eating my grilled cheese sandwich mid-bite to wonder “Huh? Why in the world would they do that?”
Seems this week’s Nature is reporting that researchers in Japan have managed to genetically engineer the green fluorescent protein gene into primates – specifically marmosets. Yes, these endearingly cute little monkeys have been engineered to express the gene in their hair roots, skin and blood, all of which glow green under UV light sources.
Now, I can understand why tropical fish aficionados might want several tetras of each color (they’ve got several now) in their aquarium to impress friends, neighbors and potential mates, but glowing green marmosets? You’ve got to have a primate license to own any kind of monkey or ape! The researchers responsible for this development say that this feat of genetic engineering could lead to monkeys being bred with genetic changes that would make them good animal models of human diseases.
Popularity: 21% [?]
Why Some People Beat the Flu
Apr 2 at 8:08pm by Aileen
…and other people die
If your family managed to get through this year’s flu season intact, you’re probably considering yourself very lucky. The A strains claim tens of thousands of lives every year, while hundreds of thousands of people who get infected manage to bounce right back in a week or two. Researchers at the Helmholtz Center for Infection Research in Germany has conducted experiments using 7 strains of genetically identical mice that led the somewhat surprising conclusion that very serious infection and death from influenza is primarily an autoimmune malfunction.
The research, published in the Public Library of Science [PLoS-One] on line, demonstrates that an excessive immune response to the virus is responsible for fatal outcomes of the disease in mice, and that this immune overreaction is genetically linked.
After infecting mice from the seven genetic lineages with identical strains the Influenza A virus, the researchers were surprised to discover very strong differences in the progression of the disease. In five of the seven mouse lineages the illness was quite mild, while in two the animals lost weight rapidly and died within just a few days.
“The mice die from their own immune defenses, which are actually supposed to protect them against the virus,” says Klaus Schughart, head of the Experimental Mouse Genetics research group. “The immune system produces too many messengers, which have a strong activating effect on the immune cells. These cells then kill tissue cells in the lungs that are infected with the virus. It appears that the animals have specific receptors on their cells that make them more receptive to a severe viral infection.”
If the results can be extended by further research to humans, it may be possible to identify people who are much more likely to die of influenza due to specific genetic makeup, so that protecting them during flu season can be made a priority. While certain at-risk populations are advised to get their flu shots annually – including doctors and nurses most likely to be exposed to the virus – identifying who among the at-risk populations is most likely to develop a hyperactive and potentially fatal autoimmune response could make better use of flu vaccine supplies by targeting them to the right people.
Links:
Why Some People Shake Off the Flu
Host Genetic Background Strongly Influences the Response to Influenza A Virus Infections
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John McCain Finally Answers the Science Questions
Sep 15 at 3:03pm by Aileen
As the Excitement of the national party conventions fades and we move into the debate phase, Republican Presidential candidate John McCain has submitted his responses to the 14 questions posed by the crew at Science Debate 2008. Democrat Barack Obama submitted his responses previously, and the SD08 website now has the two candidate’s responses listed side by side for easy comparison.
It would be great to see some of these questions come up in the debates, so that follow-ups to the positions could be explored.
Popularity: 25% [?]
Barack Obama Answers the Science Questions
Aug 30 at 11:11pm by Aileen
Democratic Presidential candidate Barack Obama has submitted his Answers to the Top 14 Science Questions facing America. Drawing on the expertise of a squadron of science, economic, foreign policy and educational advisors that includes several committed Nobel Laureates, many will be happy to get the religious and political ideology out of the way and really start addressing these issues.
Please go to the ScienceDebate 2008 website, take a hard look at Obama’s answers for our future, and don’t forget to drop the crew a dime (or ten) on your way out. These folks have been hard at it since November of last year, and have gathered some very impressive institutional support. The future is important to all of us – and our children – and the future needs the very best science we can possibly field to meet it head-on.
Popularity: 33% [?]
Rewriting the Bird Family Geneology
Jun 30 at 8:08pm by Aileen
Bird-watching is one of the most popular pastimes in the world, for people from all walks of life. Our fascination with birds in all their sizes, colors and habitats thus makes for a ready field of study in biology, where bird evolution used to maintain a fairly rigorous tree-of-life.
Not so much any longer, since researchers with the Early Bird Assembling the Tree-of-Life Project centered on the Field Museum examined DNA from all major living groups of birds and discovered that phylogenics had it all wrong!
Huge Genome Phylogenic Study of Birds Re-Writes Bird Evolution
As an indicator of just how wrong it was, DNA analysis has determined that falcons – those swift and trainable birds of prey – are NOT closely related to hawks and eagles. Whoa. Spokespersons for the project say the entire understanding of bird evolution will need to be re-written with this new information, and that information itself raises some further questions about concurrent and repeated evolution of certain traits at different times in different families.
“We now have a robust evolutionary tree from which to study the evolution of birds and all their interesting features that have fascinated so many scientists and amateurs for centuries,” Reddy said. “Birds exhibit substantial diversity (largest of the tetrapod groups), and using this ‘family tree’ wwe can begin to understand how this diversity originated as well as how different bird groups are interrelated.”
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Evolution’s Practical Joke is Still Funny
May 12 at 6:06pm by Aileen
…after all these years
That great practical joke that life’s designer [be it blind nature or purposeful god] played is still with us to confound orderly notions of biological evolution. The genome of Australia’s duck-billed platypus has been sequenced by an international group of scientists led by researchers at Washington University School of Medicine in St. Louis.
The venomous, egg-laying, duck-billed, web-footed, beaver-tailed mammal is one of the earliest offshoots of the mammalian lineage from when it split off from primitive ancestors some 166 million years ago. The genome confirms the chimeric status of this odd animal which displays traits of reptiles, birds and mammals.
As part of their analysis, researchers compared the platypus genome with human, mouse, dog, opossum and chicken genomes. Chicken genome was chosen because it represents a group of egg-laying animals that includes extinct reptiles that passed on much of their DNA to mammals over the course of evolution. When analyzed, the genetic sequences for venom production in the male platypus was found to have arisen from duplications in a group of genes evolved from ancestral reptilian genomes. They hypothesize that duplications in those very same genes led to the evolution of venom independently in modern reptiles.
The project involved sequencing about 2.2 billion base pairs and 18,500 genes. The Platypus has 52 chromosomes and an unusual 10 sex chromosomes. The platypus X chromosome also bears a striking similarity to the sex chromosome of birds.
Final conclusion? The duck-billed platypus is just as bizarre a mix-and-match critter genetically as it appeared to be when the first specimens were shown to the scientific community some 200 years ago. Skeptics then believed the animal was someone’s idea of a practical joke hoax. Turns out it really is a genetic practical joke, but it comes as-is in nature.
Links:
Platypus Genome Explains Animal’s Peculiar Features
Daily Mail: It’s a bird, it’s a beaver…
Popularity: 21% [?]
World’s Oldest Tree is a Spruce in Sweden
Apr 21 at 9:09pm by Aileen
Most school children have at one time or another encountered a photo of a twisted bristlecone pine tree in California purporting to have begun its life before Abraham left Ur [the 'Methuselah' tree at ~4767 years old]. Science Daily reported last week that a spruce tree has been discovered in the Dalarna province of Sweden that is twice that age!
Yes, this not very old-looking little tree has been dated by researchers at Umeå University’s physical geography department at ~9550 years old. Just as interesting is that this ancient tree is a genetically identical clone of a previous tree – from whose roots it sprouted all those many years ago – and which left a few scraps of old wood in the area for researchers to analyze and a laboratory in Miami, Florida to date via C-14.
Researchers combing the Swedish mountains from Lapland to Dalarna have discovered a cluster of about 20 spruces that are all more than 8,000 years old. Which has to qualify the grove as the most ancient stand of virgin timber on the planet.
Popularity: 20% [?]
The Hindu Goddess Baby
Apr 9 at 11:11pm by Aileen
For something different and profound, consider the case of a baby girl named Lali born near New Delhi, India on March 11. She has a rare birth defect called diprosopus that gave her two faces on one head. ABC News reported that the resident medical officer of the Saifi Hospital where Lali was born has thus far been unsuccessful in his attempts to convince the parents to allow CT scans or MRI to determine whether there are duplicated internal organs or invisible, life threatening deformities that might be corrected by surgery.
Most babies with this condition are stillborn or die shortly after birth, but Lali so far has shown no breathing or digestion difficulties, both mouths are being fed. She was born normally and left the hospital with her mother 8 hours after birth.
This condition is not technically a case of cojoined twinning, where a single embryo duplicates and does not completely separate. Rather, it is due to malfunctioning in the developing embryo of a single protein called Sonic hedgehog homolog [SHH]. SHH protein governs the width of the face and features, and governs proper development of the brain and spinal cord via a signaling cascade.
Popularity: 28% [?]
Genes and Not-Genes: Human Genome Shrinks Again
Jan 16 at 5:05pm by Aileen
Human Genome loses nearly 5,000 genes
Back before the human genome had been sequenced biologists estimated that we might have up to 150,000 genes to work with. Genes are those stretches of DNA code sequences between “start” and “stop” codons that are transcribed and used to create functional proteins from amino acids. High initial estimates of how many genes it takes to be a human were the natural result of a “gene-centric” point of view in biology, which assumed that all the particular traits of any organism would be determined by specific genes for those traits. We now know that things are more complicated than that.
When the first draft of the human genome was published in 2001 the approximate number of genes had been pared down – somewhat surprisingly to many – to a mere ~35,000 genes. That number has been whittled down even further over the next few years, and now has been reduced yet again by nearly 5,000. Current estimate: a mere 20,500 genes in the entire human genome.
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